1. Technical Field
The present invention relates to data stream transmission management and, more particularly, to managing the transmission of a data stream between a wired and a wireless network.
2. Description of the Related Art
In recent years, due to the popularity of mobile devices, there has been a significant proliferation of wireless networks such as 3G/4G wireless networks, WiMAX (Worldwide Interoperability for Microwave Access) and WiFi (Wireless Fidelity) networks and others. In particular, there has been considerable interest in managing transmission rates over wireless networks that are used as a “last mile” connection between mobile devices and wired networks. Management of transmission rates on the “last mile” is important, as bandwidth or capacity on wireless networks is usually much lower than the bandwidth available on the wired portion of the connection. Typically, rate matching and rate shaping methods are used to address capacity limitations on wireless data links.
In the context of video and audio traffic, rate matching adaptive techniques can be categorized into end-to-end, dynamic in-network transcoding and base station scheduling approaches. End-to-end approaches typically feedback link capacity characteristics or video/audio quality metrics from the client mobile device to the source to enable the source to lower the video/audio rate to minimize video/audio distortion. Conversely, dynamic in-network transcoding approaches perform transcoding based on feedback at an intermediate node in the wired network.
Various rate shaping methods have been developed to partly address the capacity mismatch between wired networks and wireless networks, especially in the context of differentiated services. For example, certain shapers determine priorities for dropping packets at downstream Internet nodes (i.e. routers) if network capacity is scarce. In these works, the goal is to smooth traffic based on a minimum and maximum rate promised to the user.